1. Summary of the Invention
The present disclosure relates to impinging jet air flow ovens. More particularly, the present disclosure relates to impinging jet ovens using larger orifices to carry a high mass flow of air to a food product.
2. Description of the Related Art
Impingement ovens are primarily used in quick service restaurants for rapid cooking of foods such as pizzas, finish heating of plated meals, pre-cooked meals, cookies, protein foods and the like.
Such ovens have jets of heated air which impinge directly upon the surface of the food being cooked. All jets within an oven typically have the same diameter. The ovens typically have an air handling system, to supply and distribute the heated air to the jets and thus the food, and a heating space in which the food is actually cooked.
The food is typically passed into and through the heating space by one or more conveyors per oven. These conveyors can be all in the same vertical plane or can be in multiple planes vertically.
Heated air jets are presented to the food product so that the air jets impinge directly on both the top and bottom of the food product. An energy source and an air moving source supply air to a duct. The duct has a plurality of plates comprising a plurality of orifices. The air jets are formed by air flowing through these orifices. The plates, often referred to as columnating plates, form the jets into a column to be focused/directed onto the food product.
As the demand for reduced cooking and serving times has become greater in cooking applications, it has become necessary to improve the impingement energy application, and to operate in less time than conventional impingement heating equipment, thereby increasing the speed at which the foods can be cooked.
In addition, since the amount of floor space taken up by impingement ovens is of concern in commercial kitchens, it is important to process higher volumes of food product in the same amount of floor space, thus optimizing the effective cooking area within the oven.
Conventional impinging jets can operate with orifice sizes of ⅜″ to 7/16″, approximately 3″ to 4″ away from the food product to be cooked. One method previously considered to increase the output and efficiency of the oven was to operate the heating process at as great a temperature difference between the product temperature and the oven temperature as possible, which accelerates the transfer of heat. However, with this method, smaller orifices in a 3″ to 4″ proximity to a food product cause overheating of the food product surface very quickly. This is due to the velocity of the heat being transferred via the small diameter of the contact area per orifice. Air coming through the smaller orifices travels at high velocity onto the surface of the food product, resulting in rapid removal of surface moisture and the overcooking of the product, thus producing undesirable surface coloration and charring of the food product.
Accordingly, there is a need for a new design for an impinging air jet that addresses the problems of currently available systems.